In some food handling facilities, a spiral conveyor system may be used for conveying food products. The spiral conveyor system (or “spiral”) includes a large vertical shaft that is rotated by a motor and gear box. In some facilities, the vertical shaft of the spiral is connected to a cage system that is used to convey the food products in a spiraling motion. The shaft and cage may rise 15 feet or more above the ground and may weigh 8,000 to 20,000 pounds. Therefore, a very large amount of weight might be placed on the motor, much more that it may be designed to bear. As a result of the excessive weight, the motor and gear box, sometimes costing tens of thousands of dollars, may wear down quickly and require replacement on a regular basis, which can be costly for the food handling facility.
Other than food handling facilities, other systems may have vertical-shaft motors and/or gearboxes that bear large amounts of weight. In these systems, it is desirable to minimize the load placed on the motors in order to lengthen the lifespan of the motors.
Furthermore, maintenance may occasionally be required on the spiral conveyor systems and/or other vertical shaft systems. For instance, to replace a motor or bearing at the bottom of the shaft in these vertical shaft systems, it may be necessary to raise the spiral about 18 inches to allow the shaft to be removed. In some systems where the spiral already extends up close to the ceiling of a refrigeration room, it may be necessary to cut a hole in the roof to raise the shaft high enough that the motor or bearing can be replaced. Therefore, as a consequence of the potential time and cost involved in replacing the motor or bearing, another need arises in vertical shaft systems to provide a bearing that can be easily replaced without the extensive dismantling of the spiral or cutting into the roof.